If you're looking for manga similar to Bokura wa Satsuibiyori (Light Novel), you might like these titles.
At a prestigious girl’s school, a student has died. Itsumi was the most beautiful, charismatic, and popular girl at St. Mary’s Academy for Girls. She was also the president of the exclusive and tight-knit Literature Club. One week after her death, the members of her beloved club gather in her memory. But as they each testify to what happened in the days leading up to the tragic event, their accusations turn shocking—Why, and how, did Itsumi really die?
"There is no such thing as everlasting love." Being involved in a certain incident, Nonomura Tsukumo became Chiyoda Momose, aka the break up detective's assistant. "Break up detective" chooses the detective reasoning club's activity room as home base. The two's objective is to find out the truth behind their client's break up. Because of the break up detective's rumor spreading around school, more and more clients come to seek their aid. Solving the lovelorn mysteries, a youthfulness campus reasoning story.